Higgs self-coupling measurements at the LHC

317

407

Now that the Higgs boson has been observed by the ATLAS and CMS experiments at the LHC, the next important step would be to measure accurately its properties to establish the details of the electroweak symmetry breaking mechanism. Among the measurements which need to be performed, the determination of the Higgs self-coupling in processes where the Higgs boson is produced in pairs is of utmost importance. In this paper, we discuss the various processes which allow for the measurement of the trilinear Higgs coupling: double Higgs production in gluon fusion, vector boson fusion, double Higgs-strahlung and associated production with a top quark pair. We first evaluate the production cross sections for these processes at the LHC with center-of-mass energies ranging from the present √ s = 8 TeV to √ s = 100 TeV, and discuss their sensitivity to the trilinear Higgs coupling. We include the various higher order QCD radiative corrections, at next-to-leading order for gluon and vector boson fusion and at next-to-next-to-leading order for associated double Higgs production with a gauge boson. The theoretical uncertainties on these cross sections are estimated. Finally, we discuss the various channels which could allow for the detection of the double Higgs production signal at the LHC and estimate their potential to probe the trilinear Higgs coupling.

“…[81][82][83][84][85]. An important part of this analysis will depend on the ability to reconstruct the b quark pair and the τ pair.…”

Section: The Bbττ Decay Channelmentioning

confidence: 99%

Section: Jhep04(2013)151mentioning

confidence: 99%

Section: The Bbw + W − Decay Channelmentioning

confidence: 99%

See 1 more Smart Citation

The measurement of the Higgs self-coupling at the LHC: theoretical status

Baglio

Djouadi

Gröber

et al. 2013

317

407

“…There also exists tree level diagram bb → hh, but its contribution is negligible due to the low component of b quark in proton-proton colliders, and to be consistent with the processes generated in the following Monte Carlo (MC) simulation we do not consider it here. In the SM and many new physics models, the contributions from box diagrams are dominated , and the top quark contribution is much larger than that from b quark [45][46][47][48][49][72][73][74][75][76][77][78][79][80][81][82][83][84][85][86][87]. In the MDM we checked that, the top quark contribution is still much larger than that from the b quark and top partner.…”

Section: Higgs Pair Production and Its Detection At The Hadron Collidermentioning

confidence: 99%

Higgs phenomenology in the Minimal Dilaton Model after Run I of the LHC

Cao

et al. 2014

The Minimal Dilaton Model (MDM) extends the Standard Model (SM) by a singlet scalar, which can be viewed as a linear realization of general dilaton field. This new scalar field mixes with the SM Higgs field to form two mass eigenstates with one of them corresponding to the 125 GeV SM-like Higgs boson reported by the LHC experiments. In this work, under various theoretical and experimental constrains, we perform fits to the latest Higgs data and then investigate the phenomenology of Higgs boson in both the heavy dilaton scenario and the light dilaton scenario of the MDM. We find that: (i) if one considers the ATLAS and CMS data separately, the MDM can explain each of them well, but refer to different parameter space due to the apparent difference in the two sets of data. If one considers the combined data of the LHC and Tevatron, however, the explanation given by the MDM is not much better than the SM, and the dilaton component in the 125-GeV Higgs is less than about 20% at 2σ level.(ii) The current Higgs data have stronger constrains on the light dilaton scenario than on the heavy dilaton scenario. (iii) The heavy dilaton scenario can produce a Higgs triple self coupling much larger than the SM value, and thus a significantly enhanced Higgs pair cross section at hadron colliders. With a luminosity of 100 fb −1 (10 fb −1 ) at the 14-TeV LHC, a heavy dilaton of 400 GeV (500 GeV) can be examined. (iv) In the light dilaton scenario, the Higgs exotic branching ratio can reach 43% (60%) at 2σ (3σ) level when considering only the CMS data, which may be detected at the 14-TeV LHC with a luminosity of 300 fb −1 and the Higgs Factory.

“…For example, in minimal SUSY models the maximum value of the tree-level quartic is obtained for tan β → ∞, and is about half of the standard model value. A small quartic coupling implies a small cubic Higgs coupling, which reduces the destructive interference in Higgs pair production and thus can be observed at the high-luminosity LHC [32][33][34][35]. On the other hand, as discussed above, this scenario also predicts additional Higgs bosons with sizable couplings to standard-model particles, and these are potentially observable with lower luminosity.…”

Section: Jhep03(2015)017mentioning

confidence: 99%

Phenomenology of induced electroweak symmetry breaking

Chang

Galloway

Luty

et al. 2015

Abstract:We study the phenomenology of models of electroweak symmetry breaking where the Higgs potential is destabilized by a tadpole arising from the coupling to an "auxiliary" Higgs sector. The auxiliary Higgs sector can be either perturbative or strongly coupled, similar to technicolor models. Since electroweak symmetry breaking is driven by a tadpole, the cubic and quartic Higgs couplings can naturally be significantly smaller than their values in the standard model. The theoretical motivation for these models is that they can explain the 125 GeV Higgs mass in supersymmetry without fine-tuning. The auxiliary Higgs sector contains additional Higgs states that cannot decouple from standard model particles, so these models predict a rich phenomenology of Higgs physics beyond the standard model. In this paper we analyze a large number of direct and indirect constraints on these models. We present the current constraints after the 8 TeV run of the LHC, and give projections for the sensitivity of the upcoming 14 TeV run. We find that the strongest constraints come from the direct searches A 0 → Zh, A 0 → tt, with weaker constraints from Higgs coupling fits. For strongly-coupled models, additional constraints come from ρ + → W Z where ρ + is a vector resonance. Our overall conclusion is that a significant parameter space for such models is currently open, allowing values of the Higgs cubic coupling down to 0.4 times the standard model value for weakly coupled models and vanishing cubic coupling for strongly coupled models. The upcoming 14 TeV run of the LHC will stringently test this scenario and we identify several new searches with discovery potential for this class of models.